Many new devices include voice assistant software with the capability to receive and execute voice commands. The ongoing trend of enabling voice commands has largely contributed to the ongoing trend of wearable devices, smart vehicles, and home automation systems. Voice assistants, like those provided by various smartphones, are well known and have become a part of our everyday lives. The features provided by voice assistants are useful, especially in scenarios where touch interfaces are inconvenient or even dangerous to use (e.g., while driving). Nevertheless, the open nature of the voice channel makes voice assistants difficult to secure and thus are exposed to various attacks.
Voice as an input mechanism is inherently insecure as it is prone to replay, sensitive to noise, and easy to impersonate. Existing voice authentication mechanisms fail to provide comprehensive security features for voice assistant systems. Further, even established security features, like voice-as-biometric, contain flaws. The lack of robust security for voice-assistant systems has somewhat stifled the growth of such systems, especially because the security flaws can lead to severe attacks including information theft, financial harm and unauthorized access to smart appliances and vehicles.